@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, const char *@var{bin_prefix}, const char *@var{prefix})
-Given three strings @var{progname}, @var{bin_prefix}, @var{prefix}, return a string
-that gets to @var{prefix} starting with the directory portion of @var{progname} and
-a relative pathname of the difference between @var{bin_prefix} and @var{prefix}.
-
-For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta}, @var{prefix}
-is @code{/alpha/beta/gamma/omega/}, and @var{progname} is @code{/red/green/blue/gcc},
-then this function will return @code{/red/green/blue/../../omega/}.
-
-The return value is normally allocated via @code{malloc}. If no relative prefix
-can be found, return @code{NULL}.
+Given three paths @var{progname}, @var{bin_prefix}, @var{prefix},
+return the path that is in the same position relative to
+@var{progname}'s directory as @var{prefix} is relative to
+@var{bin_prefix}. That is, a string starting with the directory
+portion of @var{progname}, followed by a relative pathname of the
+difference between @var{bin_prefix} and @var{prefix}.
+
+If @var{progname} does not contain any directory separators,
+@code{make_relative_prefix} will search @env{PATH} to find a program
+named @var{progname}. Also, if @var{progname} is a symbolic link,
+the symbolic link will be resolved.
+
+For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta},
+@var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is
+@code{/red/green/blue/gcc}, then this function will return
+@code{/red/green/blue/../../omega/}.
+
+The return value is normally allocated via @code{malloc}. If no
+relative prefix can be found, return @code{NULL}.
@end deftypefn
int prog_num, bin_num, prefix_num;
int i, n, common;
int needed_len;
- char *ret, *ptr;
+ char *ret, *ptr, *full_progname = NULL;
if (progname == NULL || bin_prefix == NULL || prefix == NULL)
return NULL;
- prog_dirs = split_directories (progname, &prog_num);
- bin_dirs = split_directories (bin_prefix, &bin_num);
- if (bin_dirs == NULL || prog_dirs == NULL)
- return NULL;
-
/* If there is no full pathname, try to find the program by checking in each
of the directories specified in the PATH environment variable. */
- if (prog_num == 1)
+ if (lbasename (progname) == progname)
{
char *temp;
#endif
)
{
- free_split_directories (prog_dirs);
progname = nstore;
- prog_dirs = split_directories (progname, &prog_num);
- if (prog_dirs == NULL)
- {
- free_split_directories (bin_dirs);
- return NULL;
- }
break;
}
}
}
+ full_progname = lrealpath (progname);
+ if (full_progname == NULL)
+ return NULL;
+
+ prog_dirs = split_directories (full_progname, &prog_num);
+ bin_dirs = split_directories (bin_prefix, &bin_num);
+ free (full_progname);
+ if (bin_dirs == NULL || prog_dirs == NULL)
+ return NULL;
+
/* Remove the program name from comparison of directory names. */
prog_num--;